Breast cancer occurs when malignant cells form in breast tissues. The most common types are ductal carcinoma (begins in the breast duct cells), lobular carcinoma (begins in the breast lobes or lobules), and inflammatory breast cancer (occurs when cancer cells block the lymph vessels in the skin and causes the breast to be warm, red, and swollen).

Primary malignant breast cancer in a female is classified to ICD-9-CM category 174 and includes Paget’s disease of the breast and nipple. A fourth digit subcategory identifies the site of the malignancy as follows:

• 174.0, Nipple and areola;

• 174.1, Central portion;

• 174.2, Upper-inner quadrant;

• 174.3, Lower-inner quadrant;

• 174.4, Upper-outer quadrant;

• 174.5, Lower-outer quadrant;

• 174.6, Axillary tail;

• 174.8, Other specified sites of female breast including ectopic sites, inner breast, lower breast, midline of the breast, outer breast, upper breast, and contiguous or overlapping sites of the breast whose point of origin cannot be determined; and

• 174.9, Female breast, unspecified.

More than one code from category 174 may be assigned if the patient has breast cancer in different sites in one or both breasts. However, if a patient has bilateral breast cancer of the same site, only one diagnosis code should be assigned. It is inappropriate to assign a diagnosis code twice on the same admission (AHA Coding Clinic for ICD-9-CM, 1989, fourth quarter, page 11).

Malignant neoplasm of the breast documented as carcinoma in situ is classified to code 233.0. Assign code 217 for a benign neoplasm of the breast. The following are the appropriate code assignments for a neoplasm diagnosis of the breast skin:

• 172.5, Malignant melanoma of skin of breast;

• 173.5, Primary malignant neoplasm of skin of breast;

• 198.2, Secondary malignant neoplasm of skin of breast;

• 232.5, Carcinoma in situ of skin of breast; and

• 216.5, Benign neoplasm of skin of breast.

Symptoms
Common breast cancer symptoms can include a lump or mass in the breast or armpit that is often painless, firm to hard, and usually has irregular borders; abnormal, clear, or bloody discharge from the nipple; the retraction or indentation of the nipple; a change in breast size or shape; and redness or pitting of the skin over the breast. Other conditions that may cause changes or lumps include fibrocystic disease of the breast (610.1), a breast cyst (610.0), breast fibroadenomas (217), mastitis (611.0), and microcalcifications identified by a mammogram (793.81).

Diagnosis
Once breast cancer is suspected, the physician may choose to perform several diagnostic tests, including biopsy. The different types of biopsies that may be performed are needle biopsy or fine-needle aspiration biopsy (85.11), which removes breast tissue using a thin needle; incisional breast biopsy (85.12), which removes part of a lump or suspicious tissue; or excisional breast biopsy, the code assignment of which will depend on the specific procedure performed. Assign code 85.12 if only a portion of the lump was removed and code 85.21 if the entire lesion or lump was excised.

There are several approaches by which a biopsy may be performed, such as stereotactic, mammotome, core, and wire localization. While these biopsies utilize different techniques, they are essentially needle biopsies and will be classified to code 85.11 unless the documentation supports that an open biopsy (85.12) or lumpectomy (85.21) was performed.

Treatment
Treatment options include a lumpectomy (85.21), which removes only the lump plus a surrounding area of normal tissue, or a partial or segmental mastectomy (85.23). Code 85.22 will be assigned if the procedure is documented as excision of a quadrant of breast.

In both procedures (sometimes documented as breast sparing), area lymph nodes may be excised. Lymph nodes in the breast area are found around the axilla, above the collarbone, and in the chest. If area lymph nodes are excised, an additional procedure code may be assigned. Simple excision of lymph nodes is classified to code 40.29, with 40.23 assigned for a simple excision of axillary lymph nodes. Code 40.3 is assigned if the procedure is documented as regional lymph node excision with excision of lymphatic drainage area, including skin, subcutaneous tissue, and fat, regardless of site.

Sometimes, a sentinel lymph node biopsy is performed. Typically, breast cancer first spreads to the axillary lymph nodes. The sentinel node is the first node to receive the drainage from breast tumors and is therefore the first to develop cancer. When the sentinel lymph node is identified by a radioactive solution, it is removed and tested for cancer. Assign code 40.23 for a sentinel lymph node biopsy (AHA Coding Clinic for ICD-9-CM, 2002, second quarter, page 7).

The following are the types of mastectomies that may be performed:

• A simple mastectomy (85.41 for unilateral or 85.42 for bilateral) is the complete excision of the breast.

• A modified radical mastectomy (85.43 for unilateral or 85.44 for bilateral) is the complete excision of the breast, including the axillary lymph nodes but not the pectoral muscle.

• A radical mastectomy (85.45 for unilateral or 85.46 for bilateral) is the complete excision of the breast, including the regional lymph nodes, pectoral muscle, and adjacent tissues.

The patient may also undergo a combination of chemotherapy and radiation, hormone, or biological therapies before or after surgery.

Coding and sequencing for breast cancer are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to nearly 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.